1. Field of the Invention
The present invention relates generally to small, three wheeled, operator propelled vehicles, and more specifically to the class of vehicle known as xe2x80x9ccambering vehicles,xe2x80x9d in which forward motion is provided by the alternating shifting of weight from side to side as the vehicle travels a sinusoidal path, due to the conservation of angular momentum. One embodiment of the present cambered vehicle includes a novel yoke linkage between the two trailing arms for the rear wheels, which links the two trailing arms together for alternating motion. The easily removable yoke also provides for ease of folding of the vehicle for storage. In another embodiment, a transverse, rocking link is provided in lieu of the yoke, with the link incorporating elastomeric end bushings to provide for relative movement between the arms and the ends of the link. The link is not conveniently removable, but the arms include folding means for compact storage of the vehicle.
2. Description of the Related Art
A type of operator propelled three wheeled vehicle known as al xe2x80x9ccambering vehiclexe2x80x9d has a single steerable front wheel and a pair of laterally spaced rear wheels on trailing arms which are articulated to the front column from which the front wheel extends. As the vehicle travels a sinusoidal path, the operator shifts his or her weight to the inside of each turning arc, thus shifting the center of mass to the inside of each arc. This results in a series of accelerations due to the conservation of momentum of the vehicle and operator. In this manner, forward motion is attained.
The above principle of propulsion is well known, as described in at least one of the issued patents discussed further below. Such vehicles utilize various mechanisms (cables and pulleys, gears, bellcranks, etc.) to link the two trailing arms together, with such mechanisms being cited in the related art discussed further below. However, the present cambered vehicle differs from those of the prior art in that it utilizes a novel yoke mechanism to link the motion of the two trailing arms together, with the yoke also providing for ease of folding of the present vehicle by means of the removal of a single fitting. Another embodiment comprises a transverse link, with elastomeric bushings at each end for arm attachment. The bushings provide the resilience required for relative motion between the ends of the link and the arms.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,045,048 issued on Aug. 30, 1977 to Clarence C. Irwin, titled xe2x80x9cTrailing Arm Cambering Vehicle With Stabilizer Linkage Having Locking Means For Parking And Stowage,xe2x80x9d describes a cambering vehicle in which the trailing arms are linked to a bellcrank which is pivotally attached to the front column well above the attachment point of the arms to the front column. The two arms are linked to the bellcrank by pushrods. A locking plate having an arcuate slot therein with a threaded locking pin extending therethrough, permits a threaded knob to be tightened to lock the mechanism in a stationary position for upright storage of the vehicle. The folding mechanism is relatively complex in comparison to the present vehicle, in that Irwin requires both of the bellcrank connecting links to be removed. Moreover, Irwin does not disclose any form of elastomeric connection between any of the fittings or mechanisms of his cambering vehicle, as provided in one embodiment of the present invention.
U.S. Pat. No. 4,047,732 issued on Sep. 13, 1977 to Jerry K. Williams et al., titled xe2x80x9cCambering Vehicle With Hydraulic Stabilizer And Equalizer,xe2x80x9d describes a vehicle similar to that of the Irwin ""048 U.S. Patent discussed immediately above, but having interconnected hydraulic cylinders linking the two trailing arms, rather than a mechanical linkage. The system functions similarly to that of the Irwin ""048 U.S. Patent, with the extension of one cylinder causing the retraction of the opposite cylinder. A valve is used to shut off the flow of hydraulic fluid between the two struts to lock the position of the vehicle as desired. The valve may also be adjusted to allow fluid to flow from one end to the other of the two cylinders, thereby allowing both cylinders to collapse simultaneously for folding the vehicle. The present vehicle avoids fluids and hydraulics, utilizing a yoke member for connecting the two trailing arms, and moreover does not require any form of intermediate links between the trailing arms and the yoke. Williams et al. do not disclose any form of elastomeric fittings or connectors attaching any of the cambering components together, as provided in an embodiment of the present invention.
U.S. Pat. No. 4,050,711 issued on Sep. 27, 1977 to Richard E. Denzer, titled xe2x80x9cCambering Device For Cambering Vehicle,xe2x80x9d describes a trailing arm interconnect mechanism having two opposed arms disposed about a single pivot. The arms may be locked together to form a bellcrank to provide opposite action of the two trailing arms, or may be folded to allow the front column to be folded to the trailing arms for storage of the device. As in the other cambering vehicles discussed above, the Denzer vehicle links the trailing arms to the actuating mechanism by connecting rods, rather than using a direct yoke or transverse link mechanism as in the present vehicle.
U.S. Pat. No. 4,050,712 issued on Sep. 27, 1977 to Richard E. Denzer et al., titled xe2x80x9cCambering Device For Cambering Vehicle,xe2x80x9d describes a mechanism very similar to that of the ""711 U.S. Patent to the same first inventor, discussed immediately above. The device of the ""712 Patent differs in that the central mechanism comprises a pair of meshed sector gears which may be locked together to provide the alternating action of the two trailing arms and their links to the mechanism. Unlocking the gears allows the forward structure to be folded adjacent to the two trailing arms. The device differs from the present cambering vehicle mechanism, with its single yoke or transverse link configuration.
U.S. Pat. No. 4,050,713 issued on Sep. 27, 1977 to Jerry K. Williams, titled xe2x80x9cCambering Device For Cambering Vehicle,xe2x80x9d describes a mechanism similar to that of the ""048 U.S. Patent to Irwin, discussed further above. The device of the ""713 Patent comprises a pair of arcuate bellcranks which may be locked together to provide the opposite lifting and descending action of the two trailing arms, with the locking means allowing the two bellcranks to be arcuately folded together for folding the forward structure adjacent the trailing arms for storage.
U.S. Pat. No. 4,054,300 issued on Oct. 18, 1977 to Frank J. Winchell, titled xe2x80x9cCambering Vehicle With Trailing Arms Interconnected By Geared Stabilizer And Equalizer Mechanism,xe2x80x9d describes a mechanism comprising a pair of opposed sector bevel gears disposed upon each pivot shaft of the trailing arms, with a central spur gear linking the two sector gears to provide equal and opposite arcuate movement of the trailing arms. The mechanism includes locking means for parking the vehicle, and means for releasing the gears to allow for folding the front structure adjacent the trailing arms. No yoke or transverse link mechanism is provided. The Winchell vehicle differs further in that it includes an engine driving the front wheel, which teaches away from the conservation of angular momentum principle of operation of unpowered cambering vehicles, including the present vehicle.
U.S. Pat. No. 4,065,146 issued on Dec. 27, 1977 to Richard E. Denzer, titled xe2x80x9cCambering Device For Cambering Vehicle,xe2x80x9d describes a mechanism similar to that described in the ""713 U.S. Patent discussed further above. A pair of bellcranks works between opposite links to the two trailing arms, to cause the trailing arms to work opposite one another, as is known in the cambering vehicle art. The two bellcranks may be adjusted relative to one another to allow the vehicle to fold, in the manner generally described in the ""713 U.S. Patent. As in the case of the ""713 U.S. Patent and others known to the present inventor, no yoke or transverse elastomeric end link means is disclosed.
U.S. Pat. No. 4,071,261 issued on Jan. 31, 1978 to Frank J. Winchell, titled xe2x80x9cLock Bar For Cambering Vehicle,xe2x80x9d describes a mechanism quite similar to that described in the ""711 U.S. Patent discussed further above, but including a lock bar which may be installed between the two trailing arms to secure them together for parking the vehicle. Again, no yoke mechanism is provided for tying together the motion of the two trailing arms, as provided by the present cambering vehicle mechanism. Winchell incorporates a transverse bellcrank, but the crank communicates with the two arms by means of a pair of generally vertically disposed links, rather than directly. Moreover, Winchell does not disclose any form of elastomer in the crank ends, as provided by the present invention.
U.S. Pat. No. 4,076,270 issued on Feb. 28, 1978 to Frank J. Winchell, titled xe2x80x9cFoldable Cambering Vehicle,xe2x80x9d describes a trailing arm interconnect mechanism comprising a continuous cable run, with an idler pulley serving to reverse the direction of travel of the cable about the opposite trailing arm pulleys. The Winchell ""270 U.S. Patent also discloses a bellcrank trailing arm interconnect system similar to that described in the ""711 U.S. Patent discussed further above, and further discloses an engine powered embodiment similar to that of the ""300 U.S. Patent to the same inventor, discussed further above. Again, no yoke or transverse link mechanism is provided for linking the two trailing arms, as provided in the present cambering vehicle invention.
U.S. Pat. No. 4,087,104 issued on May 2, 1978 to Frank J. Winchell et al., titled xe2x80x9cMethod Of Manually Propelling A Cambering Vehicle,xe2x80x9d describes a pulley system for interconnecting the two trailing arms, essentially the same as that described in the ""270 U.S. Patent discussed immediately above. The ""104 U.S. Patent also describes the principle of conservation of angular momentum for the operation of cambered vehicles, and includes a skate equipped embodiment.
U.S. Pat. No. 4,087,106 issued on May 2, 1978 to Frank J. Winchell, titled xe2x80x9cCambering Vehicle,xe2x80x9d describes various embodiments incorporating the cable actuation, motor power, and skate and ski equipped embodiments generally disclosed in the ""270 and ""104 U.S. Patents to the same inventor, and discussed above. Although a throttle control lever is provided, no brake means is disclosed.
U.S. Pat. No. 4,087,108 issued on May 2, 1978 to Frank J. Winchell, titled xe2x80x9cCambering Vehicle With Trailing Arms Interconnected By Spur Gearing,xe2x80x9d describes a mechanism in which the two pivot axles of the trailing arms are non-concentric with one another, and are interconnected by mating gears. A motorized embodiment is also disclosed, similar to that of the ""300, ""270, and ""106 U.S. Patents to the same inventor, discussed above. As in those patents and others with which the present inventor is familiar, no yoke or transverse elastomeric end link mechanism for interconnecting the two trailing arms, is disclosed in the ""108 U.S. Patent, and while a declutching lever is provided, no brake control lever is disclosed.
U.S. Pat. No. 4,088,338 issued on May 9, 1978 to Frank J. Winchell et al., titled xe2x80x9cCambering Vehicle With Cable Stabilizer And Equalizer,xe2x80x9d describes a vehicle utilizing a pulley system for linking the two trailing arms, similar to the mechanisms disclosed in the ""270 and ""104 U.S. Patents to the same first inventor, discussed further above. The same distinctions noted between those devices and the present invention are seen to apply here.
U.S. Pat. No. 4,123,079 issued on Oct. 31, 1978 to Edward J. Biskup, titled xe2x80x9cOccupant Propelled Cambering Vehicle,xe2x80x9d describes one embodiment wherein the two trailing arms are resiliently interconnected by means of a torsion bar between the two trailing arm pivot axles, and another embodiment wherein the trailing arms are resilient. In both cases the resilient means allows the arms to move independently of one another, unlike the yoke interconnect and rigid trailing arms of the present invention. In the case of the transverse link of one embodiment of the present invention, the present link includes resilient bushings at each end thereof which fit into passages in the respective left and right trailing arms. These bushings provide resilience to allow articulation both angularly and torsionally, which the torsion bar of the Biskup ""079 Patent cannot do.
U.S. Pat. No. 4,133,551 issued on Jan. 9, 1979 to Edward J. Biskup, titled xe2x80x9cCambering Device For Cambering Vehicle,xe2x80x9d describes a trailing arm interconnect mechanism comprising a crank arm having oppositely offset cranks which ride in slots in the opposite trailing arms. As one crank arm travels in one direction, the opposite crank arm travels in the opposite direction, thereby causing the two trailing arms to work opposite to one another. Again, no yoke or transverse elastomeric end link mechanisms are provided.
U.S. Pat. No. 4,165,093 issued on Aug. 21, 1979 to Edward J. Biskup, titled xe2x80x9cOccupant Propelled Cambering Vehicle,xe2x80x9d describes torsionally resilient interconnect means for the two trailing arms, essentially the same as the interconnect means disclosed in the ""079 U.S. Patent. The ""093 Patent is a division of the ""079 U.S. Patent discussed further above, and the same points raised in that discussion are seen to apply here as well.
U.S. Pat. No. 4,540,192 issued on Sep. 10, 1985 to L. H. Shelton, titled xe2x80x9cThree-Wheeled Scooter-Type Vehicle,xe2x80x9d describes a different principle of operation for such tricycle type vehicles, in which the two rear wheels remain in the same plane, but caster inwardly and outwardly with the two trailing arms also moving laterally inwardly and outwardly relative to one another. The operation is similar to skating or cross country skiing, in which the skate or ski is angled relative to the path of travel, with lateral thrust developing a forward thrust vector to propel the skier, skater, or (in the present case) vehicle forward. This principle of operation does not apply to the present vehicle.
U.S. Pat. No. 5,039,121 issued on Aug. 13, 1991 to Donovan A. Holter, titled xe2x80x9cTri-Skater,xe2x80x9d describes a tricycle type vehicle in which the two trailing arms are immovably affixed to the front structure during operation. A single brake is provided on the front wheel, rather than independent brakes for the two rear wheels. The principle of operation is thus more closely related to the vehicle of the ""192 U.S. Patent, discussed immediately above, than to the present vehicle invention.
U.S. Pat. No. 5,785,331 issued on Jul. 28, 1998 to Mark Rappaport, titled xe2x80x9cDual-Footboard Scooter,xe2x80x9d describes a tricycle type vehicle having a rigid frame, with the two rear wheels having fixed axles with no camber, caster, toe-in, or toe-out. The device is operated as a conventional scooter by pushing and coasting. A single brake is provided for the front wheel, whereas the present vehicle includes independent brakes for each rear wheel.
Finally, German Patent Publication No. 2,413,377 published on Oct. 2, 1975 illustrates a scooter and vertically undulating track, with the operator shifting his/her weight forwardly and rearwardly to shift the center of gravity of the vehicle over the crest of an undulation and thereby coast down the opposite side. The device of the German Patent Publication is constructed in the reverse of the present invention, with two forward wheels and one rearward wheel, and the frame is rigid, thus precluding any cambering action or operation by conservation of angular momentum.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.
The present invention comprises a cambering vehicle, wherein forward motion is achieved by lateral shift of the operator""s weight to the inside of the turn as the vehicle travels a sinusoidal path. Due to the principle of conservation of angular momentum, the weight shift is partially translated to forward motion in the direction of travel. The above principle is well known, with numerous cambering vehicles utilizing various mechanisms to link the two trailing arms of the vehicle together to provide the desired action. However, the present vehicle utilizes different novel embodiments of components for linking the two trailing arms together, to provide advances in simplicity, durability, and ease of folding for storage over the relatively complex linkages and mechanisms of the prior art.
In a first embodiment, a novel yoke mechanism for linking the two trailing arms together is provided. The yoke mechanism of the present cambering vehicle provides several advantages in a single mechanism, by (1) linking the two trailing arms to articulate equally and oppositely to one another, (2) providing for folding of the vehicle for storage by the removal of a single fastener, and (3) enabling the vehicle to be provided with a simple, fixed stop means to limit the travel of the two trailing arms. The present cambering vehicle also has a separate brake for each rear wheel, with each brake being independently actuated by separate levers by the vehicle operator.
A second embodiment utilizes a lateral rocking link which is essentially permanently secured to the rear of the steering column. The link has elastomeric bushings in each end thereof, which secure in cooperating passages in the respective arms. The elastomer bushings provide the required resilience to allow the arms to rotate torsionally about their connections with the link, and also to allow the required angular movement between the link and the arms. The elastomer bushings also provide a centering action for the vehicle for greater stability, and eliminate need for any form of stand or support for holding the vehicle in an upright position when parked. Folding may be accomplished by means of appropriate lockable hinge or other mechanisms in the arms. While the present cambering vehicle is primarily supported by wheels, it will be seen that the principle of operation need not be limited to rollers or wheels, but may be applied to skis, skates, etc. as well.
Accordingly, it is a principal object of the invention to provide an improved cambering vehicle incorporating a yoke for interconnecting the two trailing arms to provide equal and opposite articulation thereof.
It is another object of the invention to provide an improved cambering vehicle which yoke mechanism is quickly and easily removable to provide for the folding of the vehicle for storage.
It is a further object of the invention to provide an improved cambering vehicle including stop means for limiting the arcuate travel of the two trailing arms.
Yet another object of the invention is to provide an improved cambering vehicle incorporating a lateral link with elastomeric end bushings connecting resiliently to the two trailing arms.
An additional object of the invention is to provide an improved cambering vehicle including independent brakes for the rear wheels, with the two brakes being actuated by separate controls to provide at least some steering or turning guidance for the vehicle.
Still another object of the invention is to provide an improved cambering vehicle incorporating wheels, but which operating principle may be applied to skis, skates, and other sliding surface contact means.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.